Residual flood risk behind levees has led to what behavioral concern?

• A. Residual flood risk behind levees creates a perceived safety zone that encourages development
• B. Residual risk behind levees has no economic impact
• C. Levees eliminate flood risk entirely
• D. Levees remove the need for flood risk maps

Answer: (A)

When protective infrastructure lowers the chance of a flood, people tend to adjust their behavior in ways that can increase overall risk, a idea often called risk compensation. Levees reduce the likelihood of flooding in the protected area, but they don’t eliminate the possibility of flood events or levee failures. That creates a perceived safety zone, which can encourage more development and higher-value building in the floodplain because the area seems safer than it actually is. The result is higher exposure and potential losses if the levee is breached or overtopped.

So, the behavioral concern is that residual flood risk behind levees spurs development and investment in the protected area, based on an overestimation of safety. The other statements either ignore the economic effects of risk perception, wrongly claim risk is eliminated, or suggest flood risk maps aren’t needed, which isn’t accurate.